This invention relates to gas-fueled ovens and has particular reference to gas-fueled ovens which are capable of assuming relatively high temperatures such as may occur, for example, during a pyrolytic self-clean operation. It is known that pyrolytic cleaning operations cause the temperature of the inner walls of the oven to reach levels of as much as 900.degree.-1100.degree. F. or higher.
Obviously when the inner walls of the oven reach such high temperature levels, the heat tends to radiate or be convected or conducted to outer walls, thereby raising the outer walls to undesirably high and possibly unsafe temperature levels. Attempts have been made to overcome this problem by supplying additional baffling to prevent some of the internally generated heat from contacting the outer wall structure. Other attempts to overcome or reduce the problem included the use of one or more fans to blow cool air through the spaces between the inner and outer walls.
In gas-fueled ovens, the exhaust of hot combustion gases must also be taken into consideration. Such gases, including combustion products, usually are allowed to escape through the top or back walls of the oven. This poses an especially severe problem in built-in wall ovens where the surrounding wall or cabinet structures may be damaged. This problem has been partially overcome by providing means for exhausting the combustion flue gases through the front of the oven, usually just above the oven door. Such exhaust may be facilitated by a fan or blower. However, in such cases the exhausted gases are extremely hot and, therefore, highly undesirable for obvious reasons.
Because of the proximity of the upper or broil burner to the flue outlet in a gas-fueled range, it has been difficult to entrain primary and secondary air for combustion. This thus presented additional problems when designing an efficiently operable oven.